This invention relates to certain substituted 3-cyano quinoline compounds as well as the pharmaceutically acceptable salts thereof. The compounds of the present invention inhibit the action of certain growth factor receptor protein tyrosine kinases (PTK) and other protein kinases thereby inhibiting the abnormal growth of certain cell types. The compounds of this invention are therefore useful for the treatment of certain diseases that are the result of deregulation of these PTKs. The compounds of this invention are anti-cancer agents and are useful for the treatment of cancer in mammals. In addition, the compounds of this invention are useful for the treatment of polycystic kidney disease in mammals. This invention also relates to the manufacture of said 3-cyano quinolines, their use for the treatment of cancer and polycystic kidney disease, and the pharmaceutical preparations containing them.
Protein tyrosine kinases are a class of enzymes that catalyze the transfer of a phosphate group from ATP to a tyrosine residue located on a protein substrate. Protein tyrosine kinases clearly play a role in normal cell growth. Many of the growth factor receptor proteins function as tyrosine kinases and it is by this process that they effect signaling. The interaction of growth factors with these receptors is a necessary event in normal regulation of cell growth. However, under certain conditions, as a result of either mutation or overexpression, these receptors can become deregulated; the result of which is uncontrolled cell proliferation which can lead to tumor growth and ultimately to the disease known as cancer [Wilks A. F., Adv. Cancer Res., 60, 43 (1993) and Parsons, J. T.; Parsons, S. J., Important Advances in Oncology, DeVita V. T. Ed., J. B. Lippincott Co., Phila., 3 (1993)]. Among the growth factor receptor kinases and their proto-oncogenes that have been identified and which are targets of the compounds of this invention are the epidermal growth factor receptor kinase (EGF-R kinase, the protein product of the erbB oncogene), and the product produced by the erbB-2 (also referred to as the neu or HER2) oncogene. Since the phosphorylation event is a necessary signal for cell division to occur and since overexpressed or mutated kinases have been associated with cancer, an inhibitor of this event, a protein tyrosine kinase inhibitor, will have therapeutic value for the treatment of cancer and other diseases characterized by uncontrolled or abnormal cell growth. For example, overexpression of the receptor kinase product of the erbB-2 oncogene has been associated with human breast and ovarian cancers [Slamon, D. J., et. al., Science, 244, 707 (1989) and Science, 235, 1146 (1987)]. Deregulation of EGF-R kinase has been associated with epidermoid tumors [Reiss, M., et. al., Cancer Res., 51, 6254 (1991)], breast tumors [Macias, A., et. al., Anticancer Res., 7, 459 (1987)], and tumors involving other major organs [Gullick, W. J., Brit. Med. Bull., 47, 87 (1991)]. Because of the importance of the role played by deregulated receptor kinases in the pathogenesis of cancer, many recent studies have dealt with the development of specific PTK inhibitors as potential anti-cancer therapeutic agents [some recent reviews: Burke. T. R., Drugs Future, 17, 119 (1992) and Chang, C. J.; Geahlen, R. L., J. Nat. Prod., 55, 1529 (1992)]. The compounds of this invention inhibit the kinase activity of EGF-R and are therefore useful for treating certain disease states, such as cancer, that result, at least in part, from deregulation of this receptor. The compounds of this invention are also useful for the treatment and prevention of certain pre-cancerous conditions, such as the growth of colon polyps, that result, at least in part, from deregulation of this receptor.
It is also known that deregulation of EGF receptors is a factor in the growth of epithelial cysts in the disease described as polycystic kidney disease [Du J., Wilson P. D., Amer. J. Physiol., 269(2 Pt 1), 487 (1995); Nauta J., et al., Pediatric Research, 37(6), 755 (1995); Gattone V. H., et al., Developmental. Biology, 169(2), 504 (1995); Wilson P. D., et al., Eur. J. Cell Biol., 61(1), 131, (1993)]. The compounds of this invention, which inhibit the catalytic function of the EGF receptors, are consequently useful for the treatment of this disease.
The mitogen-activated protein kinase (MAPK) pathway is a major pathway in the cellular signal transduction cascade from growth factors to the cell nucleus. The pathway involves kinases at two levels: MAP kinase kinases (MAPKK), and their substrates MAP kinases (MAPK). There are different isoforms in the MAP kinase family. (For review, see Rony Seger and Edwin G. Krebs, FASEB, Vol. 9, 726, June 1995). The compounds of this invention can inhibit the action of two of these kinases: MEK, a MAP kinase kinase, and its substrate ERK, a MAP kinase. MEK is activated by phosphorylation on two serine residues by upstream kinases such as members of the raf family. When activated, MEK catalyzes phosphorylation on a threonine and a tyrosine residue of ERK. The activated ERK then phosphorylates and activates transcription factors in the nucleus, such as fos and jun, or other cellular targets with PXT/SP sequences. ERK, a p42 MAPK is found to be essential for cell proliferation and differentiation. Over-expression and/or over-activation of Mek or ERK has been found to be associated with various human cancers (For example, Vimala S. Sivaraman, Hsien-yu Wang, Gerard J. Nuovo, and Craig C. Malbon, J. Clin. Invest. Vol. 99, No. 7 April 1997). It has been demonstrated that inhibition of MEK prevents activation of ERK and subsequent activation of ERK substrates in cells, resulting in inhibition of cell growth stimulation and reversal of the phenotype of ras-transformed cells (David T. Dudley, Long Pang, Stuart J. Decker, Alexander J. Bridges, and Alan R. Saltiel, PNAS, Vol. 92, 7686, August 1995). Since, as demonstrated below, the compounds of this invention can inhibit the coupled action of MEK and ERK, they are useful for the treatment of diseases such as cancer which are characterized by uncontrolled cell proliferation and which, at least in part, depend on the MAPK pathway.
Epithelial Cell Kinase (ECK) is a receptor protein tyrosine kinase (RPTK) belonging to the EPH (Erythropoietin Producing Hepatoma) family. Although originally identified as an epithelial lineage-specific tyrosine kinase, ECK has subsequently been shown to be expressed on vascular endothelial cells, smooth muscle cells, and fibroblasts. ECK is a type I transmembrane glycoprotein with the extracellular ligand-binding domain consisting of a cysteine-rich region followed by three fibronectin type III repeats. The intracellular domain of ECK possesses a tyrosine kinase catalytic domain that initiates a signal transduction cascade reflecting the ECK function. ECK binds and is subsequently activated by its counter-receptor, Ligand for Eph-Related Kinase (LERK)-1, which is an immediate early response gene product readily inducible in a lineage-unrestricted manner with proinflammatory cytokines such as IL-1 or TNF. Soluble LERK-1 has been shown to stimulate angiogenesis in part by stimulating ECK in a murine model of corneal angiogenesis. Unlike their normal counterparts, tumor cells of various lineages constitutively express LERK-1 and this expression can further be upregulated by hypoxia and proinflammatory cytokines. Many of these tumor cells also express ECK at higher levels than their normal counterparts, thereby creating an opportunity for autocrine stimulation via ECK: LERK-1 interaction. The increased expression of both ECK and LERK-1 has been correlated with the transformation of melanomas from the noninvasive horizontal phase of growth into very invasive vertically growing metastatic melanomas. Together, the ECK: LERK-1 interaction is believed to promote tumor growth via its tumor growth promoting and angiogenic effects. Thus, the inhibition of the ECK tyrosine kinase activity mediating signaling cascade induced by its binding and cross-linking to LERK-1 may be therapeutically beneficial in cancer, inflammatory diseases, and hyperproliferative disorders. As is shown below, the compounds of this invention inhibit the tyrosine kinase activity of ECK and are therefore useful for the treatment of the aforementioned disorders.
Growth of most solid tumors is dependent on the angiogenesis involving activation, proliferation and migration of vascular endothelial cells and their subsequent differentiation into capillary tubes. Angiogenization of tumors allows them access to blood-derived oxygen and nutrients, and also provides them adequate perfusion. Hence inhibiting angiogenesis is an important therapeutic strategy in not only cancer but also in a number of chronic diseases such as rheumatoid arthritis, psoriasis, diabetic retinopathy, age-related macular degeneration, and so on. Tumor cells produce a number of angiogenic molecules. Vascular Endothelial Growth Factor (VEGF) is one such angiogenic factor. VEGF, a homodimeric disulfide-linked member of the PDGF family, is an endothelial cell-specific mitogen and is known to cause profound increase in the vascular endothelial permeability in the affected tissues. VEGF is also a senescence-preventing survival factor for endothelial cells. Almost all nucleated tissues in the body possess the capability to express VEGF in response to various stimuli including hypoxia, glucose deprivation, advanced glycation products, inflammatory cytokines, etc. Growth-promoting angiogenic effects of VEGF are mediated predominantly via its signaling receptor Kinase insert Domain containing Receptor (KDR). The expression of KDR is low on most endothelial cells; however, activation with angiogenic agents results in a significant upregulation of KDR on endothelial cells. Most angiogenized blood vessels express high levels of KDR. KDR is a receptor protein tyrosine kinase with an extracellular VEGF-binding domain consisting of 7 immunoglobulin-like domains and a cytoplasmic domain containing the catalytic tyrosine kinase domain split by a kinase-insert region. Binding to VEGF causes dimerization of KDR resulting in its autophosphorylation and initiation of signaling cascade. Tyrosine kinase activity of KDR is essential for mediation of its functional effects as a receptor for VEGF. Inhibition of KDR-mediated functional effects by inhibiting KDR's catalytic activity is considered to be an important therapeutic strategy in the treatment of angiogenized disease states including cancer. As is shown below, the compounds of this invention inhibit the tyrosine kinase activity of KDR and are therefore useful for the treatment of the aforementioned disease states.
In addition to the above utilities some of the compounds of this invention are useful for the preparation of other compounds of this invention.
The compounds of this invention are certain substituted 3-cyano quinolines. Throughout this patent application, the quinoline ring system will be numbered as indicated in the formula below; the numbering for the quinazoline ring system is also shown:

No 3-cyano quinolines have been reported that have biological activity as inhibitors of protein tyrosine kinases. A 3-cyano quinoline with a 4-(2-methyl anilino) substituent having gastric (H+/K+)-ATPase inhibitory activity at high concentrations has been described [Ife R. J., et al., J. Med. Chem., 35(18), 3413 (1992)].
There are quinolines that do not have the 3-cyano substituent and, unlike the compounds of this invention, are unsubstituted at the 4-position but are reported to be inhibitors of protein tyrosine kinases [Gazit A., et al., J. Med. Chem., 39(11), 2170 (1996)]. A series of quinolines that have a 3-pyridyl substituent and no substituent at the 4-position have been described as inhibitors of platelet derived growth factor receptor kinase [Dolle R. E., et al., J. Med. Chem., 372, 2627 (1994) and Maguire M. P., et al., J. Med. Chem., 372, 129 (1994)]. The patent applications WO 96/09294 and WO-9813350 describe inhibitors of protein tyrosine kinases that include 4-anilino quinolines with a large variety of substituents on positions 5-8 but which must also have a hydrogen or fluorine atom at position 3. The U.S. Pat. No. 5,480,883 describes quinoline derivatives that are inhibitors of protein tyrosine kinases but these derivatives do not have the unique combination of substituents, including the 3-cyano group, contained in the compounds of the present invention. The applications WO-9802434 and WO-9802438 describe quinoline derivatives that are tyrosine kinase inhibitors but these quinolines do not have the important 3-cyano substituent.
In addition to quinolines, certain quinazoline derivatives that are similar, in some respects, to the compounds of this invention are known to be inhibitors of protein tyrosine kinases. The application EP-520722 describes 4-anilinoquinazolines that contain simple substituents such as chloro, trifluoromethyl, or nitro groups at positions 5 to 8. The application EP-566226 is similar but with a much larger variety of substituents now allowed at positions 5 to 8. The application WO-9609294 describes compounds with similar substituents at positions 5 to 8 and with the substituent at to 4-position consisting of some polycyclic ring systems. Some simple substituted quinazolines are also described in the applications WO-9524190, WO-9521613, and WO-9515758. The applications EP-602851 and WO-9523141 cover similar quinazoline derivatives where the aryl group attached at position 4 can be a variety of heterocyclic ring structures. The application EP-635498 describes certain quinazoline derivatives that have alkenoylamino and alkynoylamino groups among the substituents at position 6 and a halogen atom at position 7. The application WO-9519774 describes compounds where one or more of the carbon atoms at positions 5-8 can be replaced with heteroatoms resulting in a large variety of bicyclic systems where the left-hand ring is a 5 and 6-membered heterocyclic ring; in addition, a variety of substituents are allowed on the left-hand ring. The application EP-682027-A1 describes certain pyrrolopyrimidine inhibitors of PTKs. The application WO-9519970 describes compounds in which the left-hand aromatic ring of the basic quinazoline structure has been replaced with a wide variety of different heterocyclic rings so that the resulting inhibitors are tricyclic. The application EP-635507 describes quinazolines where an additional 5 or 6-membered heterocyclic ring with optional substitution is fused at positions 5 and 6.
In addition to the aforementioned patent applications, a number of publications describe 4-anilinoquinazolines: Fry, D. W., et. al., Science, 265, 1093 (1994), Rewcastle G. W., et. al., J. Med. Chem., 38, 3482 (1995), and Bridges, A. J., et. al., J. Med. Chem., 39, 267, (1996). There are no publications that describe 3-cyano quinolines as PTK inhibitors.